Production of artificial silk, particularly viscose silk



May 9, 1933. H. SUTER 1,907,610

PRODUCTION OF ARTIFICIAL SILK, PARTICULARLY VISCOSE SILK Filed Dec. 5,1931 2 Sheets-Sheet l JZMa/W Jillian/or.-

ATTO RJYKY Ma'& 9, 1933. H. SUTER 1,907,610

PRODUCTION OF ARTIFICIAL SILK, PARTICULARLY VISCOSE SILK Filed Dec. 5,1931 2 Sheets-Sheet 2 44 .7/2 venfa'r Patented May 9, 1933 UNITED STATESPATENT. OFFICE HANS SUTER, F ZURICH, SWITZERLAND Application filedDecember 5, 1931, Serial No.

I have filed an application in Germany dated December 28rd, 1930.

Suggestions have already been made to collect freshly spun artificialsilk n the form '5 of loops in a slowly rotating spinning pot, and forthe purpose of producing the loops to agitate the dry spinning nozzle orthe spinning pot itself in a horizontal d rection. It has, however, notbeen possible hitherto, particularly also in the case of the wet spmnrngprocess, to introduce such a process into 1ndustry and to work up theproducts lIl a form capable of use.

According to the present process the '15 threads produced by the wetspinning process,

for example by the viscose process, are withdrawn from the spinning bathby means of a Withdrawing roller of known construction, and allowed tofall into the slowly rotating 29 spinning pot located underneath thewithdrawing roller.

It has been found by experiment that the release of the thread from thewithdrawing roller and the depositing thereof in the pot V is besteffected in a satisfactory manner if there is used a withdrawing rollerwith a distinctly toothed surface.

The spinning pot itself is removable from its driving disk, on whichitis mounted, and 39 is driven so as to rotate slowly. In order that thethread loops assume the required shape in the spinning pot and fill thepot in the desired manner the spinning pot itself receives in additionto the rotary movement also a reciprocating horizontal movement, or thethread falling into the spinning pot is allowed to fall through a threadguide to which there is imparted an alternating movement in a horizontaldirection. Finally the withdrawing roller itself may also carry out areciprocats ing horizontal movement.

A further improvement resides in the fact that the spinning pot togetherwith the rotary plate by which it is driven and on which 4.5 it ismounted, is made adjustable in height. In this manner it is possiblewhen'the filling of the pot increases to retain the same distancebetween the withdrawing roller and the top of the spinning cake. In asimilar manner 59 it is also possible to vary the position in 579,156,and in Germany December 23, 1930.

height of the depositing thread guide which is used in any case.

The pile of threads collected in the spinning pot is then advantageouslysprayed therein, and the subsequent treatment, especially in the viscoseprocess,comprisingdesulphurization, bleaching, deacidification andoiling can also be carried on within said pots. For this purpose thebottoms of the spinning pots are perforated and the interior of eachspinning pot, including the bottom, may be lined advantageously with alayer of porous cloth, for example muslin, artificial silk fabric, etc.Such lining may have the shape of a round bag, closely fitting theinterior surface of the spinning pot, with the upper rim long enough tobe folded over the edge of the pot during filling and to cover the topof the entire spinning cake after filling. After filling the pots areremovedfrom their rotary disks and are sprayed from the top eitherseparately or preferably piled one upon the other in the form of acolumn. The pots, for this latter purpose, are provided at the upperedge with a disked flange, so that it is possible to conveniently fitone pot into the upper edge of the other pot. When using the protectingcloths above referred to the upper edge of the bag is folded inwardly soas to cover the entire cake. In addition it is 30 also possible to fitinto each separate pot a perforated cover which lies directly on thespun pile or on the protecting cloth.

By such an arrangement all the desired and any other wet treatmentswhich may be necessary are carried out successively on the artificialsilk. Finally the pot is allowed to drain by gravity or is centrifuged.The finishing operation is then carried out with an oil or sizing bathwhich as regards its quantity and strength is such that a suitable anduniform sizing or oiling takes place. After renewed draining orcentrifuging it is dried. For this purpose the pots, which arepreferably perforated on all sides, may be introduced into dryingchambers or passages of known construction and subjected to the actionof hot air. Or it is feasible to use pots perforated at the bottom only,piled upon each other in the form of a column, as above described, anddry them directly by passing dry air through these columns either fromthe bottom upwards or from the top downwards. Instead of the wettreatment by spraying, the spun masses enclosed in the spinning pots;and if necessary weighted down in the protecting cloths may also besubjected to other known washing processes, for example by dipping orlixiviating or rinsing, whilst the spinning pot is either heldstationary and the liquid poured through it, or the pot is moved througha stationary bath or with any other suitable combination.

It has further been found that when it is desired to obtain a goodviscose silk attention must be paid also to the spinning bath which isused. It has been found that the most suitable spinning baths are thosewhich, in the manner of the spinning baths according to French Patent698,413, are capable of producing viscose silk which shrinks as littleas possible when being dried. In this manner the article acquires thedesired gloss, remains soft, extensible, solid and does not crimp, evenif washed and dried without tension. The effect of properly sizing thethread piles is that the separate thread stalks acquire a' cohesion andthat it is subsequently possible to work up a good silk free from down,The thread masses thus produced which are practically untwisted can bedirectly applied to reels or bobbins from the spinning pot and broughtinto any suitable assembly and wound form.

When winding the threads on reels, or bobbins directly from the pot thismay be rotated at substantially the same speed as when spinning thethreads but naturally in the opposite direction. 7

The invention will now be described with reference to the accompanyingdrawings, wherein Figure 1 shows the thread 2 coming from theprecipitating bath 1, the toothed roller 3, the thread guide 4, the pot5, the cloth 6 for enclosing the cake, the driving mechanism 7 for thepot and the device 8 for raising and lowering the pot.

The thread guide is mounted in a member 9. Its free end is provided witha roller 10 which is constantly pressed by springs 11 against a heartshaped cam 12. The heart shaped cam imparts a reciprocating movement tothe thread guide. The amount of movement of the thread guide isindicated by b.

The pot 5 is removably mounted on a plate 14 carried by a spindle 13.The spindle 13 is axially movable in a hollow shaft 15 serving 'as thedriving shaft for the pot and which isrotated by the worm drive 16. Thespindle 13 is driven by the hollow shaft 15, the key 17 of thespindleengaging a keyway in the shaft 15. This keywa-y extends along the wholelength of the hollow shaft 15.

The spindle 13 rests on a cam drum 18 which is rotated in the directionof the arrow by the worm gearing 19. A development of the cam drum isshown in Figure 1b. The edge 20 of the cam drum, of which a portion isbroken away for the sake of clearness (see dotted line in Figure 16)forms an in clined plane.

In Figure 1 the pot is shown in its highest position. When the cam drumrotates the spindle 13, according to the increase in size of the cake inthe pot, moves downwardly on the edge 20 of the drum 18. In this mannerthe distance of the thread, measured from the roller 3, is keptconstant. The size of the cake is indicated by a. The difference inheight of the edge of the drum 20 must, there fore also correspond withthe amount a.

When the spindle 13 has reached its lowest position the drum runs withits surface 21 against the spindle 13. In this manner the tooth pressurein the worm gearing 19 increases. This increasing tooth pressure may beused in well known manner for disengaging the worm 19a (on the recedingworm principle). The return of the cam drum and thus of the pot into itshighest position is effected by hand by means of the handles 22.

A screw spindle, rack gearing, a lifting cam, hydraulic pressure and soforth are to be regarded as equivalent to the cam drum.

Figure 1a shows the' method and manner in which the thread 2a isdeposited in the pot.

Figure 2 shows the manner in which the pots 5 are superposed, so as toform acolumn for the purpose of the subsequent treatment. The lowermostpot of the column rests in this case on a hollow socket 23 which,preferably with the interposition of packing, is rigidly connected to aplatform 25 provided with a suitable opening 24:.

The liquid for the subsequent treatment is supplied by the conical spray26. In order to prevent liquid being lost a short pipe section 27 isfitted on the top pot. The perforations of the spray nozzle are soarranged that only the column of cakes and not the free inner space ofthe column of cakes is supplied with liquid. The spray nozzle can beshut off.

In order to enable the liquid to pass from cake to cake the bottom 28 ofthe pots 4 is perforated. When the entire column of cakes has beentraversed by the treating liquid the liquid flows through the opening24; into the chamber 29 underneath the platform to which is connected anoutflow pipe 30 provided with a cut off valve.

If a gas, for example dry air, is to be passed through the column ofcakes the pipe 30 is first closed and the pipe section 27 is removed.The fan 31 is then set in operation and the heating device 32 is alsoset in operation.

The dry air passes through the pipe 33 into the chamber 29 and fromthere passes through the separate cakes. In order to prevent the airfrom flowing freely through the inner space of the column of cakes onlythat portion of the bottom of the pot which is covered by the cake isperforated.

The dry air can escape either into the atmosphere or be collected andrepeatedly used. In the latter case the spray 26 is removed in thedirection of the arrow and replaced by the hood 34 is moved into itsposition which is rendered possible by turning the tubular member 35.

The hood is provided with a casing 36 which can be lowered and thus cutsoff the outer atmosphere from the column of cakes, There is alsoprovided an inlet 37 for fresh air which can be controlled by a slide 38according to requirements.

A mechanical drier 39 of known construction (the moist air is caused tofollow a spiral movement therein by an impact surface and thespecifically heavier air is thus projected outwardly) serves to ensurethat dry air always enters the column of cakes.

The pipe 33 is provided with a throttle valve 40.

Figure 3 shows how the thread 2a from the pot 5 is wound on a spool 41.The pot 5 is mounted removably as in Figure 1 on a rotating disk 42 ofwhich the spindle 43 is driven by worm gearing 44. If the direction ofrotation of the pot is reversed rel ativ-ely to that which was impartedto the pot during spinning and a suitable speed of rotation is selectedit is possible to obtain a thread which is entirely free from twist.

The spool is driven in the usual manner by bevel gearing 45. The threadguide 46 is reciprocated by the forked rocking arm 47 In order that thethread 2a is guided immediately as it leaves the pot there is provided acover 48 having a central opening 49.

I claim 1. A process for the production of artificial silk, particularlyviscose silk, consisting in withdrawing freshly spun threads by means ofan auxiliary roller, which is preferably toothed, delivering the threadsin the form of loose loops into a spinning pot lined with cloth,covering the threads with said cloth, washing the threads in said potand subsequently treating them therein, drying the said threads in theloose condition and finally bringing them into wound form whilewithdrawing them from the pot.

2. A process for the production of artificial silk, particularly viscosesilk, consisting in withdrawing freshly spun threads by means of apreferably toothed auxiliary roller depositing said threads in looseloops in a slowly rotating sp nning pot lined with cloth, covering thethreads with said cloth, wash ing, subsequently treating and sizing sa dthreads in said pot, drying said threads in the loose condition andfinally working up said threads directly from the pot by Wind ing themon reels.

. 3. A process for the production. of artificial silk, particularlyviscose silk',-consisting in withdrawing freshly spun threads by meansof a preferably toothed auxiliary roller, then passing said threads inthe form step of maintaining the distance of the point.

of deposition from the Withdrawing roller and from the thread guide,whilst the spinning pot is being filled.

5. A process according to claim 1, wherein when the threads are rewounddirectly on their passage from the pot, the said pot is rotated atsubstantially the same speed or at the same speed as when spinning thethreads but in the opposite direction.

6. Apparatus for use in the production of artificial silk, particularlyviscose silk, comprising a pot for receiving the spun threads from anauxillary toothed roller, means for guiding said threads into said pot,means for driving said pot during the total period from the start to thefinish of spinning slowly and at an even rate from its highest to itslowest position, and means for lowering said pot so that the distancebetween the layer of thread and said toothed roller remains constant.

,7. Apparatus according to claim 6, wherein the means for rotating saidpot comprise a spindle, a plate on said spindle on which said pot isdetachably mounted, a hollow shaft through which said spindle passes,said hollow shaft having an internal keyway extending along the wholelength of said hollow shaft, said keyway receiving a key, fastened tothe spindle, and worm gearing operatively connected to said hollowshaft.

8. Apparatus according to claim 6, Wherein the means for loweringsaidpot comprise a cam drum, said cam drum in development forming aninclined plane, a spindle supporting said pot, said spindle co-operatingwith said cam drum, and means for rotating said cam drum.

9. Apparatus for the production of artificial silk, particularly viscosesilk, comprising a series of pots having perforated bottoms, said potsbeing superposed so as to form a column, a pipe section fitted on theuppermost pot, a hollow support supporting the column of superposedpots, a table on which said support is mounted, said table having a'hole therein adjacent said support, a collecting chamber in said table,and means for supplying finely dispersed liquid to the uppermost pot ofthe column.

10. A paratus for the production of arti ficial sil r, particularlyviscose silk comprising a pot, means for rotating said pot, means forraising and lowering said pot, a toothed roller from which thread passesto said pot and a reciprocating thread guide, actuated by an eccentricaldisk for guiding said thread into said pot in such a manner that thethread forms in the pot a star shaped cake with a hollow centralportion, the eccentricity of said thread guiding members being less thanY the radius of the spinning pot.

11. Apparatus according to claim 6, wherein said pot is lined with acloth adapted to be folded over the thread which is passed into saidpot.

In testimony whereof I afiiX my signature.

HANS SUTER.

